tially
comprehended when it is known that light, which travels from the Sun to
the Earth--a distance of ninety-three millions of miles--in eight
minutes, requires a period of four and a third years to reach us from
the nearest fixed star. A sphere having the Sun at its centre and this
nearest star at its circumference would have a diameter of upwards of
fifty billions of miles; the volume of the orb when compared with the
dimensions of this circular vacuity of space is as a small shot to a
globe 900 miles in diameter. It has been estimated by Father Secchi
that, if a comet when at aphelion were to arrive at a point midway
between the Sun and the nearest fixed star, it would require one hundred
million years in the accomplishment of its journey thither. And yet the
Sun is one of a group of stars which occupy a region of the heavens
adjacent to the Milky Way and surrounded by that zone; nor is his
isolation greater than that of those stars which are his companions, and
who, notwithstanding their profound distance, influence his movements by
their gravitational attraction, and in combination with the other stars
of the firmament control his destiny.

Ancient astronomers, for the purpose of description, have mapped out the
heavens into numerous irregular divisions called 'constellations.' They
are of various forms and sizes, according to the configuration of the
stars which occupy them, and have been named after different animals,
mythological heroes, and other objects which they appear to resemble. In
a few instances there does exist a similitude to the object after which
a constellation is called; this is evident in the case of Corona
Borealis (the Northern Crown), in which there can be seen a conspicuous
arrangement of stars resembling a coronet, and in the constellations of
the Dolphin and Scorpion, where the stars are so distributed that the
forms of those creatures can be readily recognised. There is some slight
resemblance to a bear in Ursa Major, and to a lion in Leo, and no great
effort of the mind is required to imagine a chair in Cassiopeia, and a
giant in Orion; but in the majority of instances it is difficult to
perceive any likeness of the object after which a constellation is
named, and in many cases there is no resemblance whatever.

The constellations are sixty-seven in number: excluding those of the
Zodiac, which have been already mentioned, the constellations of the
Northern Hemisphere number twenty-nine